The performance of children with autism on the Revised Extended Griffiths Scales of Mental Development
- Authors: Gowar, Rosemary Vera
- Date: 2004
- Subjects: Psychological tests for children -- South Africa , Autism in children -- South Africa , Children -- Intelligence testing -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11016 , http://hdl.handle.net/10948/353 , Psychological tests for children -- South Africa , Autism in children -- South Africa , Children -- Intelligence testing -- South Africa
- Description: Despite a widespread perception that the number of children coming to clinical attention with Autism Spectrum Disorders has greatly increased, limited South African Research has been conducted on children with Autism. Thus a need exists to accumulate knowledge about the cognitive, psychological and personalsocial growth of children diagnosed with Autism. This study is aimed at exploring the performance of children with Autism between the ages of 7 years (from 72 months) and 8 years (to 95.9 months), in South Africa (SA), utilising the Revised Extended Griffiths Scales of Mental Development (GSMD). The sample comprised an experimental group of 30 children with Autism from four schools for Specialised Education for learners with Autism in SA, and a control group comprised of 30 “normal” children, where normalcy can be broadly defined as “an absence of any sensory, physical or mental handicap”. The six areas of general development assessed included Locomotor, Personal- Social, Language, Eye and Hand co-ordination, Performance, and Practical Reasoning. A non-probability, purposive sampling method was applied. The major findings of the present study were as follows: (i) Children with Autism (years 7 & 8) showed a characteristic cognitive profile when tested with the revised Extended Griffiths Scales. Their performance indicates lower performance on Subcales B, C and F than on the other Subscales. (ii) Some children with Autism experienced major fall-outs, whereas others were slightly below average. The general performance of children with Autism was, however, in the range “cognitively impaired”. (iii) There was significant difference between the Autistic sample and the normal sample on the GQ. xiv In view of the findings, it is recommended that the results of the study, which focused on the children’s areas of developmental weakness, be widely disseminated. This could facilitate the development of therapeutic programmes, so as to allow for appropriate stimulation for children with Autism.
- Full Text:
- Date Issued: 2004
- Authors: Gowar, Rosemary Vera
- Date: 2004
- Subjects: Psychological tests for children -- South Africa , Autism in children -- South Africa , Children -- Intelligence testing -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11016 , http://hdl.handle.net/10948/353 , Psychological tests for children -- South Africa , Autism in children -- South Africa , Children -- Intelligence testing -- South Africa
- Description: Despite a widespread perception that the number of children coming to clinical attention with Autism Spectrum Disorders has greatly increased, limited South African Research has been conducted on children with Autism. Thus a need exists to accumulate knowledge about the cognitive, psychological and personalsocial growth of children diagnosed with Autism. This study is aimed at exploring the performance of children with Autism between the ages of 7 years (from 72 months) and 8 years (to 95.9 months), in South Africa (SA), utilising the Revised Extended Griffiths Scales of Mental Development (GSMD). The sample comprised an experimental group of 30 children with Autism from four schools for Specialised Education for learners with Autism in SA, and a control group comprised of 30 “normal” children, where normalcy can be broadly defined as “an absence of any sensory, physical or mental handicap”. The six areas of general development assessed included Locomotor, Personal- Social, Language, Eye and Hand co-ordination, Performance, and Practical Reasoning. A non-probability, purposive sampling method was applied. The major findings of the present study were as follows: (i) Children with Autism (years 7 & 8) showed a characteristic cognitive profile when tested with the revised Extended Griffiths Scales. Their performance indicates lower performance on Subcales B, C and F than on the other Subscales. (ii) Some children with Autism experienced major fall-outs, whereas others were slightly below average. The general performance of children with Autism was, however, in the range “cognitively impaired”. (iii) There was significant difference between the Autistic sample and the normal sample on the GQ. xiv In view of the findings, it is recommended that the results of the study, which focused on the children’s areas of developmental weakness, be widely disseminated. This could facilitate the development of therapeutic programmes, so as to allow for appropriate stimulation for children with Autism.
- Full Text:
- Date Issued: 2004
The performance of hearing impaired children on the Revised Extended Griffiths Scales
- Authors: Schröder, Ingrid Anita
- Date: 2004
- Subjects: Psychological tests for children -- South Africa , Griffiths Developmental Scales , Deaf children -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11031 , http://hdl.handle.net/10948/333 , Psychological tests for children -- South Africa , Griffiths Developmental Scales , Deaf children -- South Africa
- Description: In this unique time of nation building in South Africa, education is seen as the key foundation stone to prosperity and development. However, despite a decade of restructuring, many differing groups of children still do not receive the quality of education they deserve. Amongst those are children with special needs, including those who have a hearing impairment. These children are the focus of the present study. It is a widely accepted principle that early assessment and intervention is necessary to maximise a child’s potential. It is for this reason that the global aim of this study was to explore and describe the developmental profile of hearing impaired children on the Revised Extended Griffiths Scales. Further aims were to compare the performance of the clinical sample to a normal South African sample. A quantitative, exploratory-descriptive research design was employed. The sample of hearing impaired children (N = 58), between the ages of 36 and 95 months, attended the Carel du Toit Pre-School in the Western Cape, South Africa and were obtained by means of a non-probability, purposive sampling procedure. The normal sample (N = 58) was drawn from an existing database created for the revision of the Scales. Information was collated using clinical files, biographical data as well as the results of an assessment on the Revised Extended Griffiths Scales. The major findings of the study are summarised below. The general performance of the hearing impaired sample on the Revised Extended Griffiths Scales was average. The performance of the children on the six subscales ranged from below average to average, with major fall-outs occurring on the Hearing and Speech and Practical Reasoning Subscales. The normal sample performed significantly better than the hearing impaired sample on all of the subscales of the measure. However, significant differences were found on four of the six subscales, namely, the Locomotor, Personal-Social, Hearing and Speech and Practical Reasoning Subscales. Generally, the results of the current study suggest that a specific developmental profile is obtained for hearing impaired children. In addition, this study has highlighted the success with which the Revised Extended Griffiths Scales can be utilised on a hearing impaired population.
- Full Text:
- Date Issued: 2004
- Authors: Schröder, Ingrid Anita
- Date: 2004
- Subjects: Psychological tests for children -- South Africa , Griffiths Developmental Scales , Deaf children -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11031 , http://hdl.handle.net/10948/333 , Psychological tests for children -- South Africa , Griffiths Developmental Scales , Deaf children -- South Africa
- Description: In this unique time of nation building in South Africa, education is seen as the key foundation stone to prosperity and development. However, despite a decade of restructuring, many differing groups of children still do not receive the quality of education they deserve. Amongst those are children with special needs, including those who have a hearing impairment. These children are the focus of the present study. It is a widely accepted principle that early assessment and intervention is necessary to maximise a child’s potential. It is for this reason that the global aim of this study was to explore and describe the developmental profile of hearing impaired children on the Revised Extended Griffiths Scales. Further aims were to compare the performance of the clinical sample to a normal South African sample. A quantitative, exploratory-descriptive research design was employed. The sample of hearing impaired children (N = 58), between the ages of 36 and 95 months, attended the Carel du Toit Pre-School in the Western Cape, South Africa and were obtained by means of a non-probability, purposive sampling procedure. The normal sample (N = 58) was drawn from an existing database created for the revision of the Scales. Information was collated using clinical files, biographical data as well as the results of an assessment on the Revised Extended Griffiths Scales. The major findings of the study are summarised below. The general performance of the hearing impaired sample on the Revised Extended Griffiths Scales was average. The performance of the children on the six subscales ranged from below average to average, with major fall-outs occurring on the Hearing and Speech and Practical Reasoning Subscales. The normal sample performed significantly better than the hearing impaired sample on all of the subscales of the measure. However, significant differences were found on four of the six subscales, namely, the Locomotor, Personal-Social, Hearing and Speech and Practical Reasoning Subscales. Generally, the results of the current study suggest that a specific developmental profile is obtained for hearing impaired children. In addition, this study has highlighted the success with which the Revised Extended Griffiths Scales can be utilised on a hearing impaired population.
- Full Text:
- Date Issued: 2004
The relationship between job satisfaction and absenteeism : a study of the shop floor workers in a motor manufacturing plant
- Authors: Mashonganyika, Oswald
- Date: 2004
- Subjects: Job satisfaction -- South Africa -- Eastern Cape Absenteeism (Labor) -- South Africa -- Eastern Cape Automobile industry and trade -- South Africa -- Eastern Cape -- Employees Industrial relations -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:809 , http://hdl.handle.net/10962/d1007518
- Description: This research hypothesises a statistical positive significant correlation between job satisfaction and absenteeism among the shop floor workers of a motor manufacturing plant in the impoverished province of the Eastern Cape in South Africa. According to the literature review, two schools of thought exist that argue on the nature of the relationship. One believes that absence from work is in some way a natural consequence of job dissatisfaction, i.e. arguing for a job satisfaction-absenteeism relationship. The second one argues for a no relationship, arguing that absence is a result of habitual behaviour and or behaviours influenced by socioeconomic factors such as poverty that affect the employees' ability and pressure to attend work. A sample of 150 workers was randomly selected from the 2500 shop floor workers. The Job Descriptive Index (lDI) questionnaires were used to measure the satisfaction index of the workers. The absence statistics for the sample workers were gathered from the organisation's Human Resources department and statistical tests for correlation and regression were conducted on the two variables - lDI and absence data. Contrary to the expectations of the study, the results showed that overall job satisfaction and absenteeism were not correlated. It concluded that the job dissatisfaction theory of absenteeism is empirically unsupportable and alternative conceptualisations of absence contributors and potentially fruitful research strategies are discussed.
- Full Text:
- Date Issued: 2004
- Authors: Mashonganyika, Oswald
- Date: 2004
- Subjects: Job satisfaction -- South Africa -- Eastern Cape Absenteeism (Labor) -- South Africa -- Eastern Cape Automobile industry and trade -- South Africa -- Eastern Cape -- Employees Industrial relations -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:809 , http://hdl.handle.net/10962/d1007518
- Description: This research hypothesises a statistical positive significant correlation between job satisfaction and absenteeism among the shop floor workers of a motor manufacturing plant in the impoverished province of the Eastern Cape in South Africa. According to the literature review, two schools of thought exist that argue on the nature of the relationship. One believes that absence from work is in some way a natural consequence of job dissatisfaction, i.e. arguing for a job satisfaction-absenteeism relationship. The second one argues for a no relationship, arguing that absence is a result of habitual behaviour and or behaviours influenced by socioeconomic factors such as poverty that affect the employees' ability and pressure to attend work. A sample of 150 workers was randomly selected from the 2500 shop floor workers. The Job Descriptive Index (lDI) questionnaires were used to measure the satisfaction index of the workers. The absence statistics for the sample workers were gathered from the organisation's Human Resources department and statistical tests for correlation and regression were conducted on the two variables - lDI and absence data. Contrary to the expectations of the study, the results showed that overall job satisfaction and absenteeism were not correlated. It concluded that the job dissatisfaction theory of absenteeism is empirically unsupportable and alternative conceptualisations of absence contributors and potentially fruitful research strategies are discussed.
- Full Text:
- Date Issued: 2004
The relationship between trait anxiety and anxiety sensitivity
- Authors: Farrington, Robin Mark
- Date: 2004
- Subjects: Anxiety sensitivity -- South Africa , Anxiety -- South Africa -- Testing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11021 , http://hdl.handle.net/10948/352 , Anxiety sensitivity -- South Africa , Anxiety -- South Africa -- Testing
- Description: Anxiety Sensitivity (AS) is a useful psychological construct in understanding the development of general and clinical anxiety. An increased amount of research has recently been conducted in this area. Since the development of the 16-item Anxiety Sensitivity Index (ASI), there has been deliberation in the literature about the relationship of the AS construct and the ASI, to the personality construct of trait anxiety. Central to this discus sion is the notion that AS is nothing more than trait anxiety. This position brings into question the conceptual and empirical validity of AS. This study aimed to explore and describe the relationship between trait anxiety and anxiety sensitivity, through the use of an exploratory-descriptive correlational design. Levels of trait anxiety were determined through the use of subscales on the Sixteen Personality Factor Questionnaire (16PF) and anxiety sensitivity through the use of the ASI. Using a convenience sampling technique, 84 student volunteers completed the 16PF and ASI. Descriptive statistics and inferential statistics were employed for data analysis. The results indicate that the sample group had the capacity to express emotional energy along integrated channels and was thus well suited for exploring the relationship between the construct of trait anxiety and anxiety sensitivity. The relationship between trait anxiety and AS in the sample group was explored through the use of two statistical procedures. Firstly, the coefficient of determination (r²) was calculated and revealed that 24% of the variance among the ASI scores were attributable to variations in Factor QII scores of the 16PF and viceversa. Secondly, a multiple regression analysis technique revealed that 28% of the variance in the ASI score could be explained by the combination of factors Q4 (free- floating anxiety), O (guilt proneness), C (ego strength), L (suspiciousness), Q3 (ability to bind anxiety) of the 16PF. These key findings are in line with other research in that the constructs of trait anxiety and anxiety sensitivity showed a level of variance. As such, it was concluded that although the constructs may be related, they are not synonymous.
- Full Text:
- Date Issued: 2004
- Authors: Farrington, Robin Mark
- Date: 2004
- Subjects: Anxiety sensitivity -- South Africa , Anxiety -- South Africa -- Testing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11021 , http://hdl.handle.net/10948/352 , Anxiety sensitivity -- South Africa , Anxiety -- South Africa -- Testing
- Description: Anxiety Sensitivity (AS) is a useful psychological construct in understanding the development of general and clinical anxiety. An increased amount of research has recently been conducted in this area. Since the development of the 16-item Anxiety Sensitivity Index (ASI), there has been deliberation in the literature about the relationship of the AS construct and the ASI, to the personality construct of trait anxiety. Central to this discus sion is the notion that AS is nothing more than trait anxiety. This position brings into question the conceptual and empirical validity of AS. This study aimed to explore and describe the relationship between trait anxiety and anxiety sensitivity, through the use of an exploratory-descriptive correlational design. Levels of trait anxiety were determined through the use of subscales on the Sixteen Personality Factor Questionnaire (16PF) and anxiety sensitivity through the use of the ASI. Using a convenience sampling technique, 84 student volunteers completed the 16PF and ASI. Descriptive statistics and inferential statistics were employed for data analysis. The results indicate that the sample group had the capacity to express emotional energy along integrated channels and was thus well suited for exploring the relationship between the construct of trait anxiety and anxiety sensitivity. The relationship between trait anxiety and AS in the sample group was explored through the use of two statistical procedures. Firstly, the coefficient of determination (r²) was calculated and revealed that 24% of the variance among the ASI scores were attributable to variations in Factor QII scores of the 16PF and viceversa. Secondly, a multiple regression analysis technique revealed that 28% of the variance in the ASI score could be explained by the combination of factors Q4 (free- floating anxiety), O (guilt proneness), C (ego strength), L (suspiciousness), Q3 (ability to bind anxiety) of the 16PF. These key findings are in line with other research in that the constructs of trait anxiety and anxiety sensitivity showed a level of variance. As such, it was concluded that although the constructs may be related, they are not synonymous.
- Full Text:
- Date Issued: 2004
The renaissance in optical spectroscopy of phthalocyanines and other tetraazaporphyrins
- Nyokong, Tebello, Isago, Hiroaki
- Authors: Nyokong, Tebello , Isago, Hiroaki
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289388 , vital:56628 , xlink:href="https://doi.org/10.1142/S1088424604000453"
- Description: Spectral properties of metallophthalocyanines and other tetraazaporphyrins are governed mainly by the Q band which originates from the π-π* transitions within the ring. The position and intensity of the Q band is important in tailoring new phthalocyanine derivatives for particular applications. Aggregation, the nature of the central metal, π conjugation, symmetry of the molecules, and axial, peripheral or non-peripheral substitutions affect the spectra and hence the properties of the phthalocyanine molecule. This review gives a brief outline on how optical spectroscopy provides useful informations on molecular and electronic structures, chemistry and physics of phthalocyanines and other tetraazaporphyrins.
- Full Text:
- Date Issued: 2004
- Authors: Nyokong, Tebello , Isago, Hiroaki
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289388 , vital:56628 , xlink:href="https://doi.org/10.1142/S1088424604000453"
- Description: Spectral properties of metallophthalocyanines and other tetraazaporphyrins are governed mainly by the Q band which originates from the π-π* transitions within the ring. The position and intensity of the Q band is important in tailoring new phthalocyanine derivatives for particular applications. Aggregation, the nature of the central metal, π conjugation, symmetry of the molecules, and axial, peripheral or non-peripheral substitutions affect the spectra and hence the properties of the phthalocyanine molecule. This review gives a brief outline on how optical spectroscopy provides useful informations on molecular and electronic structures, chemistry and physics of phthalocyanines and other tetraazaporphyrins.
- Full Text:
- Date Issued: 2004
The reproductive biology and artificial breeding of ningu Labeo victorianus (Pisces: Cyprinidae)
- Authors: Rutaisire, Justus
- Date: 2004
- Subjects: Fishes -- Victoria, Lake , Cyprinidae -- Reproduction , Labeo -- Reproduction , Labeo
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5317 , http://hdl.handle.net/10962/d1005162
- Description: Lake Victoria, the largest tropical lake, has faced an unprecedented assault on its ecosystem through a variety of anthropomorphic causes that include the introduction of Nile perch Lates niloticus and over-fishing. As a result there have been species extinctions and declining fish population trends. This thesis explores options for reversing these declining population trends and the restoration of collapsed fisheries based on indigenous non-cichlid species. A candidate species was chosen - the cyprinid fish Labeo victorianus. This thesis studied various aspects of L. victorianus' reproductive biology in two geographically distant populations. These included general reproductive patterns in relation to proximate environmental conditions, gonadal development and recrudescence, sex development, characterisation of genetic and morphological diversity, and induced spawning. Fish from both populations were found to be potamodrometic, and highly fecund, iteroparous spawners. L. victorianus was also shown to be an undifferentiated gonochorist, where all individuals pass through an intersexual juvenile stage prior to differentiation, and maturation to either sex. Sexual maturity was attained at a significantly larger size within the Kagera River than that of Sio River fish – possibly as a response to genotypic and/or phenotypic differences. Spawning seemed to be synchronised with rainfall in Kagera River - a pattern that was not strictly adhered to with the Sio River. Thorough microscopic investigation of recrudescence patterns indicated there was uninterrupted spawning in fish from the Kagera River followed by Type I oocyte atresia. In contrast, there was a 90% spawning failure, as characterised by Type II oocyte atresia, within the Sio River population. Aspects of spermatogenesis and sperm ultrastructure using light- and ultramicrotomic methods are described. Although the populations had varying reproductive biology parameters and were morphologically distinct, they remained undifferentiated at the mitochondrial level. Both populations were characterised by low nucleotide diversity – a feature attributed to a bottleneck event. The option of captive breeding was explored by conducting induced spawning experiments. Success was only achieved with a decapeptide Gonadotropic Releasing Hormone ([D-Arg⁶, Pro⁹-NEt])-sGnRH) in combination with a water-soluble dopamine receptor antagonist metoclopramide. This thesis stresses the importance of a research-oriented approach in the conservation of Lake Victoria's indigenous fish resources. It was concluded that information needed for the development of management policies can be generated within a reasonably short time period, of approximately three years, with modest levels of funding support.
- Full Text:
- Date Issued: 2004
- Authors: Rutaisire, Justus
- Date: 2004
- Subjects: Fishes -- Victoria, Lake , Cyprinidae -- Reproduction , Labeo -- Reproduction , Labeo
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5317 , http://hdl.handle.net/10962/d1005162
- Description: Lake Victoria, the largest tropical lake, has faced an unprecedented assault on its ecosystem through a variety of anthropomorphic causes that include the introduction of Nile perch Lates niloticus and over-fishing. As a result there have been species extinctions and declining fish population trends. This thesis explores options for reversing these declining population trends and the restoration of collapsed fisheries based on indigenous non-cichlid species. A candidate species was chosen - the cyprinid fish Labeo victorianus. This thesis studied various aspects of L. victorianus' reproductive biology in two geographically distant populations. These included general reproductive patterns in relation to proximate environmental conditions, gonadal development and recrudescence, sex development, characterisation of genetic and morphological diversity, and induced spawning. Fish from both populations were found to be potamodrometic, and highly fecund, iteroparous spawners. L. victorianus was also shown to be an undifferentiated gonochorist, where all individuals pass through an intersexual juvenile stage prior to differentiation, and maturation to either sex. Sexual maturity was attained at a significantly larger size within the Kagera River than that of Sio River fish – possibly as a response to genotypic and/or phenotypic differences. Spawning seemed to be synchronised with rainfall in Kagera River - a pattern that was not strictly adhered to with the Sio River. Thorough microscopic investigation of recrudescence patterns indicated there was uninterrupted spawning in fish from the Kagera River followed by Type I oocyte atresia. In contrast, there was a 90% spawning failure, as characterised by Type II oocyte atresia, within the Sio River population. Aspects of spermatogenesis and sperm ultrastructure using light- and ultramicrotomic methods are described. Although the populations had varying reproductive biology parameters and were morphologically distinct, they remained undifferentiated at the mitochondrial level. Both populations were characterised by low nucleotide diversity – a feature attributed to a bottleneck event. The option of captive breeding was explored by conducting induced spawning experiments. Success was only achieved with a decapeptide Gonadotropic Releasing Hormone ([D-Arg⁶, Pro⁹-NEt])-sGnRH) in combination with a water-soluble dopamine receptor antagonist metoclopramide. This thesis stresses the importance of a research-oriented approach in the conservation of Lake Victoria's indigenous fish resources. It was concluded that information needed for the development of management policies can be generated within a reasonably short time period, of approximately three years, with modest levels of funding support.
- Full Text:
- Date Issued: 2004
The role of management and leadership in the schooling of at-risk learners: a case study of a school in Namibia
- Authors: Ipinge, Emma
- Date: 2004
- Subjects: School management and organization -- Namibia -- Case studies Educational leadership -- Namibia -- Case studies Education and state -- Namibia School discipline -- Namibia Children with social disabilities -- Education -- Namibia Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1750 , http://hdl.handle.net/10962/d1003634
- Description: Most schools that serve learners who come from disadvantaged areas and backgrounds face unusually difficult challenges. These schools experience poor performance and disciplinary problems, and teachers lack motivation and commitment. This study explores the role of leadership and management in the schooling of at-risk learners at Pandu Primary School. This school accommodates learners mostly from Hafo, a township characterised by poverty with a high crime rate. However, in spite of these factors school inspectors and advisory teachers perceive the school to be successful. The school uses an abundance of energy and unusually high levels of human effort in a very focused way to improve the teaching and learning standard. The study found the co-existence of apparently conflicting management and leadership approaches in managing and leading the school. Strict control used in the school to make teachers work hard is an element of classical organisational theory, with its emphasis on span of control or number of workers supervised. Policies with strict rules are in place to create a calm atmosphere and serve as directives for teachers and learners. On the other hand, constructivist approaches – such as instructional leadership, transformational leadership, collegial model of management and open systems – are also clearly evident in the findings. Instructional leadership is evident in the emphasis on improvement of classroom practice. Elements of transformational leadership are seen in that the principal motivates the teachers and serves as a role model. The school also has some features of the collegial model of management, and can be described as an open system. Thus, by drawing on management and leadership approaches informed by different traditions and philosophies, the school succeeds against severe odds.
- Full Text:
- Date Issued: 2004
- Authors: Ipinge, Emma
- Date: 2004
- Subjects: School management and organization -- Namibia -- Case studies Educational leadership -- Namibia -- Case studies Education and state -- Namibia School discipline -- Namibia Children with social disabilities -- Education -- Namibia Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1750 , http://hdl.handle.net/10962/d1003634
- Description: Most schools that serve learners who come from disadvantaged areas and backgrounds face unusually difficult challenges. These schools experience poor performance and disciplinary problems, and teachers lack motivation and commitment. This study explores the role of leadership and management in the schooling of at-risk learners at Pandu Primary School. This school accommodates learners mostly from Hafo, a township characterised by poverty with a high crime rate. However, in spite of these factors school inspectors and advisory teachers perceive the school to be successful. The school uses an abundance of energy and unusually high levels of human effort in a very focused way to improve the teaching and learning standard. The study found the co-existence of apparently conflicting management and leadership approaches in managing and leading the school. Strict control used in the school to make teachers work hard is an element of classical organisational theory, with its emphasis on span of control or number of workers supervised. Policies with strict rules are in place to create a calm atmosphere and serve as directives for teachers and learners. On the other hand, constructivist approaches – such as instructional leadership, transformational leadership, collegial model of management and open systems – are also clearly evident in the findings. Instructional leadership is evident in the emphasis on improvement of classroom practice. Elements of transformational leadership are seen in that the principal motivates the teachers and serves as a role model. The school also has some features of the collegial model of management, and can be described as an open system. Thus, by drawing on management and leadership approaches informed by different traditions and philosophies, the school succeeds against severe odds.
- Full Text:
- Date Issued: 2004
The role of school management teams in school improvement
- Authors: Sister, Loliwe Fezeka
- Date: 2004
- Subjects: School management teams -- South Africa , School improvement programs -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9489 , http://hdl.handle.net/10948/372 , School management teams -- South Africa , School improvement programs -- South Africa
- Description: This study is aimed at investigating the role of the School Management Team (SMT) in school improvement. The investigation was carried out using the qualitative approach and the study is underpinned by the interpretive paradigm. The declining performance of some schools academically as reflected by the end of year results, as well as the confusion that engulfed me on assuming duty on my appointment as a head of department of Science and, therefore, becoming part of the SMT in my school, encouraged me to investigate the role of the SMT in school improvement. The study covers, among others, the following areas: § Functions performed by the SMT members. § Challenges faced by the SMT members in their management practice. § Ways of addressing these challenges. Methods of data collection used in this study were interviews, questionnaires, own observations as well as the analysis of documents. The main recommendations emanating from the study are that SMT members should be better equipped for their roles through workshops and in-service training and that the respective roles of SMT and School Governing Body (SGB) members should be better demarcated by the Department of Education.
- Full Text:
- Date Issued: 2004
- Authors: Sister, Loliwe Fezeka
- Date: 2004
- Subjects: School management teams -- South Africa , School improvement programs -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9489 , http://hdl.handle.net/10948/372 , School management teams -- South Africa , School improvement programs -- South Africa
- Description: This study is aimed at investigating the role of the School Management Team (SMT) in school improvement. The investigation was carried out using the qualitative approach and the study is underpinned by the interpretive paradigm. The declining performance of some schools academically as reflected by the end of year results, as well as the confusion that engulfed me on assuming duty on my appointment as a head of department of Science and, therefore, becoming part of the SMT in my school, encouraged me to investigate the role of the SMT in school improvement. The study covers, among others, the following areas: § Functions performed by the SMT members. § Challenges faced by the SMT members in their management practice. § Ways of addressing these challenges. Methods of data collection used in this study were interviews, questionnaires, own observations as well as the analysis of documents. The main recommendations emanating from the study are that SMT members should be better equipped for their roles through workshops and in-service training and that the respective roles of SMT and School Governing Body (SGB) members should be better demarcated by the Department of Education.
- Full Text:
- Date Issued: 2004
The role of the trade union in post democratic South Africa
- Authors: Collins, Selwyn Charles
- Date: 2004
- Subjects: Labor unions -- South Africa , Labor policy -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11036 , http://hdl.handle.net/10948/354 , Labor unions -- South Africa , Labor policy -- South Africa
- Description: In South Africa, labour has played a central role in shaping the transition to democracy. It remained an open question as to whether labour could sustain it’s involvement during the period of consolidation after the first democratic elections. As was evident in other emerging democracies, economic liberalization often led to stagnation and high costs being imposed on workers, while weakening the state. South African trade unions thus faced formidable problems as they had to respond to rapid economic and industrial change. While being stubborn, South African trade unions remain adaptable enough to survive and grow into the 21st Century. In this dissertation, the writer examines the relevance of trade unions in contemporary South Africa and how they are coming to terms with the deregulated labour market, and the question of globalisation. We look at the emergence of new forms of collective bargaining, the growth of trade unions as partners in a changing workplace and the different ways trade unions are modernising themselves to attract new members. Labour when used as a collective force is capable of shaping democratization through the strategic use of power. Labour has the potential , through participation in negotiated compromises, to ensure that the costs of adjustments are not borne by workers alone. To this end, the South African trade union movement has developed innovative strategies and institutions.
- Full Text:
- Date Issued: 2004
- Authors: Collins, Selwyn Charles
- Date: 2004
- Subjects: Labor unions -- South Africa , Labor policy -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11036 , http://hdl.handle.net/10948/354 , Labor unions -- South Africa , Labor policy -- South Africa
- Description: In South Africa, labour has played a central role in shaping the transition to democracy. It remained an open question as to whether labour could sustain it’s involvement during the period of consolidation after the first democratic elections. As was evident in other emerging democracies, economic liberalization often led to stagnation and high costs being imposed on workers, while weakening the state. South African trade unions thus faced formidable problems as they had to respond to rapid economic and industrial change. While being stubborn, South African trade unions remain adaptable enough to survive and grow into the 21st Century. In this dissertation, the writer examines the relevance of trade unions in contemporary South Africa and how they are coming to terms with the deregulated labour market, and the question of globalisation. We look at the emergence of new forms of collective bargaining, the growth of trade unions as partners in a changing workplace and the different ways trade unions are modernising themselves to attract new members. Labour when used as a collective force is capable of shaping democratization through the strategic use of power. Labour has the potential , through participation in negotiated compromises, to ensure that the costs of adjustments are not borne by workers alone. To this end, the South African trade union movement has developed innovative strategies and institutions.
- Full Text:
- Date Issued: 2004
The Southern Ocean Group at Rhodes University: seventeen years of biological oceanography in the Southern Ocean reviewed
- McQuaid, Christopher D, Froneman, P William
- Authors: McQuaid, Christopher D , Froneman, P William
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6834 , http://hdl.handle.net/10962/d1010423
- Description: This paper reviews the main findings of the Southern Ocean Group at Rhodes University over the last 17 years. A primary contribution has been the development of conceptual models of the physical-biological driving mechanisms that support enormous seasonal populations of land-based top predators at the Prince Edward Islands. Collectively, these models are referred to as the life-support system of the islands. Near-shore subcomponents of the ecosystem, including inshore feeding predators, are largely supported by autochthonous primary production of kelps and localized diatom blooms. These energy sources feed indirectly into top predator populations via the benthic communities. A crucial link is formed by the bottom-dwelling shrimp, Nauticaris marionis, which feeds largely on benthic species and detritus and is eaten by a number of diving seabirds. The frontal systems that lie north and south of the islands are important feeding grounds for offshore feeding birds. A decadal-scale southward shift in the position of the Sub-antarctic Front towards the islands is reflected in increases in populations of these species. , Rhodes Centenary issue
- Full Text:
- Date Issued: 2004
- Authors: McQuaid, Christopher D , Froneman, P William
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6834 , http://hdl.handle.net/10962/d1010423
- Description: This paper reviews the main findings of the Southern Ocean Group at Rhodes University over the last 17 years. A primary contribution has been the development of conceptual models of the physical-biological driving mechanisms that support enormous seasonal populations of land-based top predators at the Prince Edward Islands. Collectively, these models are referred to as the life-support system of the islands. Near-shore subcomponents of the ecosystem, including inshore feeding predators, are largely supported by autochthonous primary production of kelps and localized diatom blooms. These energy sources feed indirectly into top predator populations via the benthic communities. A crucial link is formed by the bottom-dwelling shrimp, Nauticaris marionis, which feeds largely on benthic species and detritus and is eaten by a number of diving seabirds. The frontal systems that lie north and south of the islands are important feeding grounds for offshore feeding birds. A decadal-scale southward shift in the position of the Sub-antarctic Front towards the islands is reflected in increases in populations of these species. , Rhodes Centenary issue
- Full Text:
- Date Issued: 2004
The streets and the gods of truth: memory
- Authors: Duiker, Sello
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454916 , vital:75386 , https://hdl.handle.net/10520/EJC146213
- Description: It is hard to believe that 10 years of democracy have passed since the new democratically elected government came into power in 1994. While growing up in the turbulent '80s, it seemed as if the reign of terror and oppression would never end. But like most things it did.
- Full Text:
- Date Issued: 2004
- Authors: Duiker, Sello
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454916 , vital:75386 , https://hdl.handle.net/10520/EJC146213
- Description: It is hard to believe that 10 years of democracy have passed since the new democratically elected government came into power in 1994. While growing up in the turbulent '80s, it seemed as if the reign of terror and oppression would never end. But like most things it did.
- Full Text:
- Date Issued: 2004
The toxic effect of heavy metals on algal biomass (Spirulina sp.) and carbonic anhydrase activity, an enzyme which is central to algal application in metal precipitation
- Authors: Nightingale, Leigh
- Date: 2004
- Subjects: Heavy metals -- Toxicology , Spirulina , Carbonic anhydrase , Algae -- Metabolism , Photosynthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4093 , http://hdl.handle.net/10962/d1007858 , Heavy metals -- Toxicology , Spirulina , Carbonic anhydrase , Algae -- Metabolism , Photosynthesis
- Description: Acid rmne drainage (AMD) is a major pollution problem througbout the world, adversely affecting both surface and groundwaters. AMD is principally associated with the mining of sulphide ores. The most commonly associated minerals being sulphur, copper, zinc, silver, gold, lead and uranium. As conventional methods for removing heavy metals from wastewater are often prohibitively expensive, the implementation of biological processes for the removal of heavy metals has become a realistic practice. The objectives of this project was firstly to establish the effect of copper, lead and nickel, heavy metals commonly found in AMD waters, on the enzyme carbonic anhydrase, which is an integral part of the carbon concentrating mechanism (CCM) and secondly, to determine the feasibility of using the alkalinity generated by Spindina for the precipitation of heavy metals from solution. Initially, batch flask experiments were performed and it was found that the algae were able to utilise the bicarbonate supplied in the medium, under CO, limiting conditions, through the induction of their CCM, resulting in the generation of carbonate. The effect of the inhibitors, acetazolamide (AZ) and ethoxyzolamide (EZ), were also investigated in order to determine the importance of carbonic anhydrase (CA) in inorganic carbon accumulation and photosynthesis. Results obtained were consistent with those observed in literature and it was found that at IOOf.LM AZ and EZ, complete inhibition of photosynthesis and carbonic anhydrase occurred, with no oxygen being evolved. The results obtained from the inhibitor experiments substantiate the findings that carbonic anhydrase is an important part of the CCM, and that the dehydration of bicarbonate to carbon dioxide and hydroxide ions, is in fact an enzymatic process regulated by the enzyme carbonic anhydrase and is essential for efficient photosynthesis. The effect of heavy metals on Spirulina was also investigated. Lead, copper and nickel were all found to cause a reduction in the synthesis of chlorophyll a, which resulted in a decrease in photosynthetic efficiency and eventually death of the culture. The morphology of the algae was also severely affected by heavy metals, with degradation and aJmost complete disintegration of the algal filaments occurring. Using the Wilbur-Anderson assay method, carbonic anhydrase activity was found to be lower in the experimental flasks containing heavy metals, than the control flasks, reducing the algae's ability to utilise the bicarbonate in solution for effective photosynthesis. The Wilbur-Anderson assay method did not prove to be a reliable method for measuring changes in enzyme activity as results were found to be erratic. Therefore attempts were made to use an oxygen electrode as an alternative method for determining the effects of various parameters on enzyme activity and photosynthesis, this proved to be more successful. Because of the toxic effects of heavy metals on Spirulina it was decided that the use of the biogenic alkalinity generated by the algae for the precipitation of heavy metals may be successfully employed as an alternative method for bioremediation and metal recovery. Carbonate reacts readily with metals, therefore the carbonate produced by this algal system was used for the precipitation of metals. It was possible to categorise the precipitation reactions observed into three groups, namely those metals which, a) precipitate as hydroxides, b) precipitate as carbonates generated from the dissociation of bicarbonate and c) metals which can only precipitate if there is free carbonate present in solution.
- Full Text:
- Date Issued: 2004
- Authors: Nightingale, Leigh
- Date: 2004
- Subjects: Heavy metals -- Toxicology , Spirulina , Carbonic anhydrase , Algae -- Metabolism , Photosynthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4093 , http://hdl.handle.net/10962/d1007858 , Heavy metals -- Toxicology , Spirulina , Carbonic anhydrase , Algae -- Metabolism , Photosynthesis
- Description: Acid rmne drainage (AMD) is a major pollution problem througbout the world, adversely affecting both surface and groundwaters. AMD is principally associated with the mining of sulphide ores. The most commonly associated minerals being sulphur, copper, zinc, silver, gold, lead and uranium. As conventional methods for removing heavy metals from wastewater are often prohibitively expensive, the implementation of biological processes for the removal of heavy metals has become a realistic practice. The objectives of this project was firstly to establish the effect of copper, lead and nickel, heavy metals commonly found in AMD waters, on the enzyme carbonic anhydrase, which is an integral part of the carbon concentrating mechanism (CCM) and secondly, to determine the feasibility of using the alkalinity generated by Spindina for the precipitation of heavy metals from solution. Initially, batch flask experiments were performed and it was found that the algae were able to utilise the bicarbonate supplied in the medium, under CO, limiting conditions, through the induction of their CCM, resulting in the generation of carbonate. The effect of the inhibitors, acetazolamide (AZ) and ethoxyzolamide (EZ), were also investigated in order to determine the importance of carbonic anhydrase (CA) in inorganic carbon accumulation and photosynthesis. Results obtained were consistent with those observed in literature and it was found that at IOOf.LM AZ and EZ, complete inhibition of photosynthesis and carbonic anhydrase occurred, with no oxygen being evolved. The results obtained from the inhibitor experiments substantiate the findings that carbonic anhydrase is an important part of the CCM, and that the dehydration of bicarbonate to carbon dioxide and hydroxide ions, is in fact an enzymatic process regulated by the enzyme carbonic anhydrase and is essential for efficient photosynthesis. The effect of heavy metals on Spirulina was also investigated. Lead, copper and nickel were all found to cause a reduction in the synthesis of chlorophyll a, which resulted in a decrease in photosynthetic efficiency and eventually death of the culture. The morphology of the algae was also severely affected by heavy metals, with degradation and aJmost complete disintegration of the algal filaments occurring. Using the Wilbur-Anderson assay method, carbonic anhydrase activity was found to be lower in the experimental flasks containing heavy metals, than the control flasks, reducing the algae's ability to utilise the bicarbonate in solution for effective photosynthesis. The Wilbur-Anderson assay method did not prove to be a reliable method for measuring changes in enzyme activity as results were found to be erratic. Therefore attempts were made to use an oxygen electrode as an alternative method for determining the effects of various parameters on enzyme activity and photosynthesis, this proved to be more successful. Because of the toxic effects of heavy metals on Spirulina it was decided that the use of the biogenic alkalinity generated by the algae for the precipitation of heavy metals may be successfully employed as an alternative method for bioremediation and metal recovery. Carbonate reacts readily with metals, therefore the carbonate produced by this algal system was used for the precipitation of metals. It was possible to categorise the precipitation reactions observed into three groups, namely those metals which, a) precipitate as hydroxides, b) precipitate as carbonates generated from the dissociation of bicarbonate and c) metals which can only precipitate if there is free carbonate present in solution.
- Full Text:
- Date Issued: 2004
The unfair labour practice relating to promotion
- Authors: Abrahams, Dawood
- Date: 2004
- Subjects: Unfair labor practices -- South Africa , Promotions -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11035 , http://hdl.handle.net/10948/329 , Unfair labor practices -- South Africa , Promotions -- South Africa , Labor laws and legislation -- South Africa
- Description: This article deals with the South African law relating to promotions. As promotion disputes mostly arise as alleged unfair labour practices, a short discussion on how the concept of an unfair labour practice developed in South Africa is undertaken. In this regard the common law is studied in order to see whether it makes provision for protection of employees subjected to unfair labour practices relating to promotions. Through this study one soon realises that the common law is in fact inadequate to deal with unfair labour practices relating to promotions, and thus an enquiry into various legislative provisions are undertaken. The impact of the all-important Wiehahn Commission of Enquiry, established in 1979, is also briefly discussed. In this article an attempt is made to define the term ‘promotion’. In this regard reference is made to some cases adjudicated upon by the Commission for Conciliation Mediation and Arbitration (the “CCMA”). The cases referred to seem to favour the view that when one is defining the term ‘promotion’, regard must be had to the employment relationship between the employer and the employee, as well as the nature of the employee’s current work in relation to the work applied for, in order to establish whether in fact a promotion has taken place. It is necessary to consider what unfair conduct is defined as in the context of promotions. It seems that managerial prerogative is at the center of the enquiry into unfair conduct of the employer. Further to the analysis of unfair conduct, various principles that govern both procedural and substantive unfairness are considered. These principles are dealt with separately with reference to case law. Lastly the dispute resolution mechanisms are considered and a brief discussion on remedies is undertaken. The remedies are discussed with reference to case law, as well as the provisions of the Labour Relations Act 66 of 1995 as amended by the Labour Relations Amendment Act 12 of 2002. The broad headings of this article are accordingly unfair labour practices, definition of promotions, unfair conduct of the employer, onus of proof and remedies. It is concluded with the proposition that once an employer has set policies and procedures in place in dealing with promotions, then such an employer should stick to those policies and procedures within the context of the law, as well as within the percepts of the vague and nebulous term of ‘fairness’. Should the employer fail to do so, the majority of cases indicate that such an employer will be guilty of an unfair labour practice relating to promotion.
- Full Text:
- Date Issued: 2004
- Authors: Abrahams, Dawood
- Date: 2004
- Subjects: Unfair labor practices -- South Africa , Promotions -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11035 , http://hdl.handle.net/10948/329 , Unfair labor practices -- South Africa , Promotions -- South Africa , Labor laws and legislation -- South Africa
- Description: This article deals with the South African law relating to promotions. As promotion disputes mostly arise as alleged unfair labour practices, a short discussion on how the concept of an unfair labour practice developed in South Africa is undertaken. In this regard the common law is studied in order to see whether it makes provision for protection of employees subjected to unfair labour practices relating to promotions. Through this study one soon realises that the common law is in fact inadequate to deal with unfair labour practices relating to promotions, and thus an enquiry into various legislative provisions are undertaken. The impact of the all-important Wiehahn Commission of Enquiry, established in 1979, is also briefly discussed. In this article an attempt is made to define the term ‘promotion’. In this regard reference is made to some cases adjudicated upon by the Commission for Conciliation Mediation and Arbitration (the “CCMA”). The cases referred to seem to favour the view that when one is defining the term ‘promotion’, regard must be had to the employment relationship between the employer and the employee, as well as the nature of the employee’s current work in relation to the work applied for, in order to establish whether in fact a promotion has taken place. It is necessary to consider what unfair conduct is defined as in the context of promotions. It seems that managerial prerogative is at the center of the enquiry into unfair conduct of the employer. Further to the analysis of unfair conduct, various principles that govern both procedural and substantive unfairness are considered. These principles are dealt with separately with reference to case law. Lastly the dispute resolution mechanisms are considered and a brief discussion on remedies is undertaken. The remedies are discussed with reference to case law, as well as the provisions of the Labour Relations Act 66 of 1995 as amended by the Labour Relations Amendment Act 12 of 2002. The broad headings of this article are accordingly unfair labour practices, definition of promotions, unfair conduct of the employer, onus of proof and remedies. It is concluded with the proposition that once an employer has set policies and procedures in place in dealing with promotions, then such an employer should stick to those policies and procedures within the context of the law, as well as within the percepts of the vague and nebulous term of ‘fairness’. Should the employer fail to do so, the majority of cases indicate that such an employer will be guilty of an unfair labour practice relating to promotion.
- Full Text:
- Date Issued: 2004
The use and performance of recycling polypropylene in lead-acid battery cases
- Authors: Rust, Nico
- Date: 2004
- Subjects: Polypropylene , Lead-acid batteries
- Language: English
- Type: Thesis , Masters , MTech (Chemistry)
- Identifier: vital:10978 , http://hdl.handle.net/10948/269 , Polypropylene , Lead-acid batteries
- Description: Polypropylene has proven to be the ideal material for the outer shell of the lead acid batteries. Due to its mold-ability and inert properties the material provides a capsule for the functioning components of the lead acid battery and can withstand a variety conditions encountered during its application, such as impact shock resistance, high and low temperatures and acid resistance. Polypropylene has however become of great concern with regards to environmental pollution since it is generally resistant to normal conditions of degradation and can only be properly disposed of by incineration. This factor has encouraged the industry to find ways to regenerate spent polypropylene. A good example of such a process is the recycling of lead acid batteries. This allows not only for the regeneration of lead, but also for the recycling of polypropylene in the manufacturing of battery cases. There are some cost advantages in using recycled polypropylene. However it does have its disadvantages in that the material does start to deteriorate after multiple processes. A common practice amongst battery manufacturers is to add virgin polypropylene to the recycled material in order to ensure performance consistency. The comparative study investigated the use of various ratios of virgin and recycled PP in the manufacturing of lead acid battery cases and their influence on the physical properties and performance of the final material. The degradation of PP was also investigated as the material was subjected to multiple manufacturing processes where the influence of stabilizers was further considered. A common technique of PP analysis such as MFI was shown to be an effective technique to maintain good quality control. The study further showed that it is important that the material grade of PP used in the manufacturing of the battery case and lid is compatible in order to allow for effective heating sealing of the two components. Polypropylene has a waxy surface finish and it is generally difficult to label or write on. Labels tend to fall off in application and make it difficult to maintain a track record of the manufactured batteries with time. This study showed successfully that a laser activated dye can be added to the PP without influencing its color or its performance. This allows for successful labeling of battery cases by various bar coding writers that can trace the battery through its manufacturing process. Lead acid batteries are often operated outside the specified temperature range that is determined by battery manufacturers resulting in premature failure. These failures can occur within the warranty period of the battery and result in illicit claims since the monitoring of the batteries in its application was not possible. A suitable temperature monitoring device was designed that would be incorporated into the vent cap or lid of the battery case. The device contained temperature sensitive indicators that would undergo a permanent color change at specified temperatures thereby giving the battery manufacturer an indication as to the maximum temperature the battery was exposed to.
- Full Text:
- Date Issued: 2004
- Authors: Rust, Nico
- Date: 2004
- Subjects: Polypropylene , Lead-acid batteries
- Language: English
- Type: Thesis , Masters , MTech (Chemistry)
- Identifier: vital:10978 , http://hdl.handle.net/10948/269 , Polypropylene , Lead-acid batteries
- Description: Polypropylene has proven to be the ideal material for the outer shell of the lead acid batteries. Due to its mold-ability and inert properties the material provides a capsule for the functioning components of the lead acid battery and can withstand a variety conditions encountered during its application, such as impact shock resistance, high and low temperatures and acid resistance. Polypropylene has however become of great concern with regards to environmental pollution since it is generally resistant to normal conditions of degradation and can only be properly disposed of by incineration. This factor has encouraged the industry to find ways to regenerate spent polypropylene. A good example of such a process is the recycling of lead acid batteries. This allows not only for the regeneration of lead, but also for the recycling of polypropylene in the manufacturing of battery cases. There are some cost advantages in using recycled polypropylene. However it does have its disadvantages in that the material does start to deteriorate after multiple processes. A common practice amongst battery manufacturers is to add virgin polypropylene to the recycled material in order to ensure performance consistency. The comparative study investigated the use of various ratios of virgin and recycled PP in the manufacturing of lead acid battery cases and their influence on the physical properties and performance of the final material. The degradation of PP was also investigated as the material was subjected to multiple manufacturing processes where the influence of stabilizers was further considered. A common technique of PP analysis such as MFI was shown to be an effective technique to maintain good quality control. The study further showed that it is important that the material grade of PP used in the manufacturing of the battery case and lid is compatible in order to allow for effective heating sealing of the two components. Polypropylene has a waxy surface finish and it is generally difficult to label or write on. Labels tend to fall off in application and make it difficult to maintain a track record of the manufactured batteries with time. This study showed successfully that a laser activated dye can be added to the PP without influencing its color or its performance. This allows for successful labeling of battery cases by various bar coding writers that can trace the battery through its manufacturing process. Lead acid batteries are often operated outside the specified temperature range that is determined by battery manufacturers resulting in premature failure. These failures can occur within the warranty period of the battery and result in illicit claims since the monitoring of the batteries in its application was not possible. A suitable temperature monitoring device was designed that would be incorporated into the vent cap or lid of the battery case. The device contained temperature sensitive indicators that would undergo a permanent color change at specified temperatures thereby giving the battery manufacturer an indication as to the maximum temperature the battery was exposed to.
- Full Text:
- Date Issued: 2004
The use of computer-based management information systems as a recruitment tool an assessment of the attitudes of recruitment agents in a selected area of the Western Cape on 10 February 2004
- Authors: Victor, Louana
- Date: 2004
- Subjects: Employment agencies -- South Africa -- Western Cape -- Evaluation , Employee selection -- South Africa -- Western Cape -- Data processing , Management information systems -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10997 , http://hdl.handle.net/10948/342 , Employment agencies -- South Africa -- Western Cape -- Evaluation , Employee selection -- South Africa -- Western Cape -- Data processing , Management information systems -- South Africa -- Western Cape
- Description: Recruitment and selection has become a specialised industry and is competing in a global market. To remain competitive, recruitment agents have to stay ahead of their competitors, by providing an excellent service to customers and applicants, and by keeping up with technological developments in their field. The current investigation focuses on an assessment of the attitudes of recruitment agents in a selected area of the Western Cape Province to the use of computer-based management information systems as a recruitment tool. A questionnaire was distributed amongst recruitment agents in the identified area. It focused on recruiter biographical information, the services they offer, the methods and processes they use in recruitment, the knowledge and skills they need in their field, and their knowledge and attitude towards electronic-recruitment. The literature indicated a move towards using technology in the field of recruitment, and this was consistent with the findings of the study. Although the respondents were familiar with developments in technology used for recruitment, only a small number were familiar with the major business information systems, namely, SAP R/3, Oracle and PeopleSoft. Information specifically related to recruitment agents in South Africa was limited, but the study provided some insight into this field. It was found that recruitment agents disagree on what a good advertisement, as well as a good résumé, should contain, and this is problematic as these are two of the most important things that recruitment agents work with every day. The literature provided no indication of the qualifications needed by a recruitment agent, and resulting from this, a second finding of the study indicated that, according to the respondents, the qualifications needed by a recruitment agent are varied. It was found that qualifications of the sample group varied from only a school-leaving certificate to post-graduate degrees. A significant trend identified that only 24.2 per cent of recruitment agents are involved in research related to recruitment, and write articles related to their field. This contributes to the fact that so little information is available about South African recruitment agents. The study indicated that recruitment agents hold a positive attitude towards computer-based information systems, although they are accepted with caution because of various logistical problems in the South African market. The study also provided useful information to start a process of drawing up a profile of the South African recruitment agency business.
- Full Text:
- Date Issued: 2004
- Authors: Victor, Louana
- Date: 2004
- Subjects: Employment agencies -- South Africa -- Western Cape -- Evaluation , Employee selection -- South Africa -- Western Cape -- Data processing , Management information systems -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10997 , http://hdl.handle.net/10948/342 , Employment agencies -- South Africa -- Western Cape -- Evaluation , Employee selection -- South Africa -- Western Cape -- Data processing , Management information systems -- South Africa -- Western Cape
- Description: Recruitment and selection has become a specialised industry and is competing in a global market. To remain competitive, recruitment agents have to stay ahead of their competitors, by providing an excellent service to customers and applicants, and by keeping up with technological developments in their field. The current investigation focuses on an assessment of the attitudes of recruitment agents in a selected area of the Western Cape Province to the use of computer-based management information systems as a recruitment tool. A questionnaire was distributed amongst recruitment agents in the identified area. It focused on recruiter biographical information, the services they offer, the methods and processes they use in recruitment, the knowledge and skills they need in their field, and their knowledge and attitude towards electronic-recruitment. The literature indicated a move towards using technology in the field of recruitment, and this was consistent with the findings of the study. Although the respondents were familiar with developments in technology used for recruitment, only a small number were familiar with the major business information systems, namely, SAP R/3, Oracle and PeopleSoft. Information specifically related to recruitment agents in South Africa was limited, but the study provided some insight into this field. It was found that recruitment agents disagree on what a good advertisement, as well as a good résumé, should contain, and this is problematic as these are two of the most important things that recruitment agents work with every day. The literature provided no indication of the qualifications needed by a recruitment agent, and resulting from this, a second finding of the study indicated that, according to the respondents, the qualifications needed by a recruitment agent are varied. It was found that qualifications of the sample group varied from only a school-leaving certificate to post-graduate degrees. A significant trend identified that only 24.2 per cent of recruitment agents are involved in research related to recruitment, and write articles related to their field. This contributes to the fact that so little information is available about South African recruitment agents. The study indicated that recruitment agents hold a positive attitude towards computer-based information systems, although they are accepted with caution because of various logistical problems in the South African market. The study also provided useful information to start a process of drawing up a profile of the South African recruitment agency business.
- Full Text:
- Date Issued: 2004
The use of environmental learning support materials to mediate learning in outcomes-based education: a case study in an Eastern Cape school
- Authors: Nduna, Nomalungelo Rosement
- Date: 2004
- Subjects: Environmental education -- South Africa -- Eastern Cape Environmental education -- Curricula -- South Africa Teaching -- Aids and devices -- South Africa Environmental education -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1812 , http://hdl.handle.net/10962/d1003698
- Description: Educational transformation and curriculum reform within the new South African Outcomes Based Education (OBE) system has introduced new roles for teachers, and a focus on environmental learning within each learning area. In an OBE system, teachers are required to mediate learning, develop learning programmes, and use a range of different learning support materials. This study aimed to explore how one teacher in an Eastern Cape school used environmental learning support materials to mediate learning within an OBE curriculum framework. Over the past ten years a number of environmental educators and researchers have been participating in curriculum policy development and curriculum implementation research. This has led to the incorporation of an environmental focus within different learning areas in Curriculum 2005. The focus on environment in the curriculum was strengthened by the introduction of the National Environmental Education Project in the General Education and Training (NEEP-GET) band in 2001. I am employed as a provincial co-coordinator within this project (for the Eastern Cape province), and one of my tasks is to work with service providers (who provide learning support materials) and teachers (who use these materials) to ensure improved environmental learning within the OBE curriculum. A qualitative and empirical case study was conducted in which I observed one teacher in a multi-grade class (with grade 6 and 7 learners) using learning support materials to achieve learning outcomes in three different lessons. The study employed a range of data collection methods such as questionnaires, interviews, field notes, video recording, and document analysis, photographs and journal entries. I compiled a contextual profile of the school and classroom and undertook two 'layers' of data analysis to report the findings of the study. This research indicates that theories of learning and associated teaching methods influence learning interactions, and the use of learning support material in the class. The study also highlighted emerging issues in the use of environmental learning support materials, which relate to planning; access to materials; over-use of materials; and the relationship between learning support materials and teaching methods.
- Full Text:
- Date Issued: 2004
- Authors: Nduna, Nomalungelo Rosement
- Date: 2004
- Subjects: Environmental education -- South Africa -- Eastern Cape Environmental education -- Curricula -- South Africa Teaching -- Aids and devices -- South Africa Environmental education -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1812 , http://hdl.handle.net/10962/d1003698
- Description: Educational transformation and curriculum reform within the new South African Outcomes Based Education (OBE) system has introduced new roles for teachers, and a focus on environmental learning within each learning area. In an OBE system, teachers are required to mediate learning, develop learning programmes, and use a range of different learning support materials. This study aimed to explore how one teacher in an Eastern Cape school used environmental learning support materials to mediate learning within an OBE curriculum framework. Over the past ten years a number of environmental educators and researchers have been participating in curriculum policy development and curriculum implementation research. This has led to the incorporation of an environmental focus within different learning areas in Curriculum 2005. The focus on environment in the curriculum was strengthened by the introduction of the National Environmental Education Project in the General Education and Training (NEEP-GET) band in 2001. I am employed as a provincial co-coordinator within this project (for the Eastern Cape province), and one of my tasks is to work with service providers (who provide learning support materials) and teachers (who use these materials) to ensure improved environmental learning within the OBE curriculum. A qualitative and empirical case study was conducted in which I observed one teacher in a multi-grade class (with grade 6 and 7 learners) using learning support materials to achieve learning outcomes in three different lessons. The study employed a range of data collection methods such as questionnaires, interviews, field notes, video recording, and document analysis, photographs and journal entries. I compiled a contextual profile of the school and classroom and undertook two 'layers' of data analysis to report the findings of the study. This research indicates that theories of learning and associated teaching methods influence learning interactions, and the use of learning support material in the class. The study also highlighted emerging issues in the use of environmental learning support materials, which relate to planning; access to materials; over-use of materials; and the relationship between learning support materials and teaching methods.
- Full Text:
- Date Issued: 2004
The value of many small vs. few large marine protected areas in the Western Solomon Islands
- Shankar, Aswani, Hamilton, Richard
- Authors: Shankar, Aswani , Hamilton, Richard
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440050 , vital:73731
- Description: Scientists and policy makers are universally promoting marine protected areas (MPAs) as a fisheries and ecosystem management tool. Experts generally agree that MPAs, particularly fully protected “no-take” zones, can enhance spawning stock biomass, allow for larval dispersal and the export of adults to adjacent non-protected areas, maintain species diversity, preserve habitat, and sustain ecosystem function (eg Bergen and Carr 2003; Johnson et al. 1999; Russ and Alcala 1999). In the case of tropical multi-species fisheries, in which absolute yields are difficult to predict and in which there are multiple users and fishing techniques, marine reserves also can act as precautionary tools to prevent overexploitation. Considering that orthodox fisheries management strategies have generally failed to prevent overfishing globally, the inception of MPAs as a management tool is of particular preventive significance (Russ 2002). Proponents of MPAs have broadly debated the appropriate size and number of MPAs that should be established in order to produce what a particular management prescription proposes to deliver. Some scientists argue that for MPAs to be effective they should cover areas in the magnitude of hundreds or even thousands of square miles, depending upon the type of environment (eg Beattie et al. 2002; Man et al. 1995; Walters 2000). Others have suggested that from a fisheries enhancement perspective, many small reserves in a network are preferred over fewer, larger reserves (eg Roberts et al. 2003). Other debates have centred on how much attention should be paid to science-driven vs. stakeholder-driven considerations when designing MPAs (eg Agardy 1997; Alder et al. 2002; Christie et al. 2003; Jones 2002).
- Full Text:
- Date Issued: 2004
- Authors: Shankar, Aswani , Hamilton, Richard
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440050 , vital:73731
- Description: Scientists and policy makers are universally promoting marine protected areas (MPAs) as a fisheries and ecosystem management tool. Experts generally agree that MPAs, particularly fully protected “no-take” zones, can enhance spawning stock biomass, allow for larval dispersal and the export of adults to adjacent non-protected areas, maintain species diversity, preserve habitat, and sustain ecosystem function (eg Bergen and Carr 2003; Johnson et al. 1999; Russ and Alcala 1999). In the case of tropical multi-species fisheries, in which absolute yields are difficult to predict and in which there are multiple users and fishing techniques, marine reserves also can act as precautionary tools to prevent overexploitation. Considering that orthodox fisheries management strategies have generally failed to prevent overfishing globally, the inception of MPAs as a management tool is of particular preventive significance (Russ 2002). Proponents of MPAs have broadly debated the appropriate size and number of MPAs that should be established in order to produce what a particular management prescription proposes to deliver. Some scientists argue that for MPAs to be effective they should cover areas in the magnitude of hundreds or even thousands of square miles, depending upon the type of environment (eg Beattie et al. 2002; Man et al. 1995; Walters 2000). Others have suggested that from a fisheries enhancement perspective, many small reserves in a network are preferred over fewer, larger reserves (eg Roberts et al. 2003). Other debates have centred on how much attention should be paid to science-driven vs. stakeholder-driven considerations when designing MPAs (eg Agardy 1997; Alder et al. 2002; Christie et al. 2003; Jones 2002).
- Full Text:
- Date Issued: 2004
The viability of small-scale farming at the Tyhefu Irrigation Scheme, Eastern Cape
- Authors: Sishuta, Happy Babalwa
- Date: 2004
- Subjects: Farms, Small -- South Africa -- Eastern Cape , Irrigation -- South Africa -- Eastern Cape , Irrigation farming -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3344 , http://hdl.handle.net/10962/d1004924 , Farms, Small -- South Africa -- Eastern Cape , Irrigation -- South Africa -- Eastern Cape , Irrigation farming -- South Africa -- Eastern Cape
- Description: This investigation is conducted against the background of current attempts to rehabilitate and revive the now defunct Tyhefu irrigation scheme. The poor track record of many irrigation schemes (despite huge investments) in the former homelands has prompted the government to reconsider its active and direct role in small-scale irrigation farming. This has resulted in the closure of many irrigation schemes including Tyhefu irrigation scheme. The new policy framework in South Africa, known as the irrigation management transfer, is premised on the transfer of ownership, authority and responsibility of small-scale irrigation schemes from government to the farmers. Tyhefu irrigation scheme was a state-driven, top-down initiative. This study argues that the justifications for the Tyhefu irrigation scheme were conflated, with the result that the need for political control of the Tyhefu area far outweighed the considerations regarding the financial viability and sustainability of the proposed project. Given the repressive political climate of the time in South Africa, the planners' proposals were a mechanism for the realization of the socio-political and economic agendas of the apartheid state and Ciskei government. Although technical factors critical for project success were examined, little or no attention was paid to the socio-economic aspects. For the planners, the main requirements for success entailed centralized managerial control, no participation of the beneficiaries, capital intensive and sophisticated agricultural techniques and the production of high value crops. Therefore, it can be argued that the nature of the planning and implementation of the Tyhefu irrigation scheme was ill-conceived, short-sighted and misguided. A review of the literature on irrigation development on the African continent provided useful insights for this study. The lessons from irrigation development experience in Sub-Saharan Africa indicate that the continent is littered with examples of derelict and costly failures. What stands out in many of these irrigation projects is their over-emphasis on technical issues to the complete neglect of human and other social aspects. Working partnerships between the farmers and irrigation scheme management could, thus, not be realized. Almost without exception the case studies used here indicate that the industrious type of farmer was never developed as was envisioned in the planning documents. Neither were rural livelihoods improved in a sustainable manner. The findings of this study suggest that irrigation management transfer is a complex and delicate process. In this new set of arrangements, beneficiaries face formidable challenges in terms of capacity (human and financial) if small-scale irrigation farming is to become a viable sector. No doubt, the viability and sustainability of the Tyhefu irrigation scheme demands a comprehensive package of interventions that address various issues of markets and marketing, capital investment and access to finance, technology, education and training, support and extension services. It is evident that institutional aspects and the related issue of functional literacy require much more attention than thus far. As a result, at the moment there is no possibility for independent agricultural production. , KMBT_363
- Full Text:
- Date Issued: 2004
- Authors: Sishuta, Happy Babalwa
- Date: 2004
- Subjects: Farms, Small -- South Africa -- Eastern Cape , Irrigation -- South Africa -- Eastern Cape , Irrigation farming -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3344 , http://hdl.handle.net/10962/d1004924 , Farms, Small -- South Africa -- Eastern Cape , Irrigation -- South Africa -- Eastern Cape , Irrigation farming -- South Africa -- Eastern Cape
- Description: This investigation is conducted against the background of current attempts to rehabilitate and revive the now defunct Tyhefu irrigation scheme. The poor track record of many irrigation schemes (despite huge investments) in the former homelands has prompted the government to reconsider its active and direct role in small-scale irrigation farming. This has resulted in the closure of many irrigation schemes including Tyhefu irrigation scheme. The new policy framework in South Africa, known as the irrigation management transfer, is premised on the transfer of ownership, authority and responsibility of small-scale irrigation schemes from government to the farmers. Tyhefu irrigation scheme was a state-driven, top-down initiative. This study argues that the justifications for the Tyhefu irrigation scheme were conflated, with the result that the need for political control of the Tyhefu area far outweighed the considerations regarding the financial viability and sustainability of the proposed project. Given the repressive political climate of the time in South Africa, the planners' proposals were a mechanism for the realization of the socio-political and economic agendas of the apartheid state and Ciskei government. Although technical factors critical for project success were examined, little or no attention was paid to the socio-economic aspects. For the planners, the main requirements for success entailed centralized managerial control, no participation of the beneficiaries, capital intensive and sophisticated agricultural techniques and the production of high value crops. Therefore, it can be argued that the nature of the planning and implementation of the Tyhefu irrigation scheme was ill-conceived, short-sighted and misguided. A review of the literature on irrigation development on the African continent provided useful insights for this study. The lessons from irrigation development experience in Sub-Saharan Africa indicate that the continent is littered with examples of derelict and costly failures. What stands out in many of these irrigation projects is their over-emphasis on technical issues to the complete neglect of human and other social aspects. Working partnerships between the farmers and irrigation scheme management could, thus, not be realized. Almost without exception the case studies used here indicate that the industrious type of farmer was never developed as was envisioned in the planning documents. Neither were rural livelihoods improved in a sustainable manner. The findings of this study suggest that irrigation management transfer is a complex and delicate process. In this new set of arrangements, beneficiaries face formidable challenges in terms of capacity (human and financial) if small-scale irrigation farming is to become a viable sector. No doubt, the viability and sustainability of the Tyhefu irrigation scheme demands a comprehensive package of interventions that address various issues of markets and marketing, capital investment and access to finance, technology, education and training, support and extension services. It is evident that institutional aspects and the related issue of functional literacy require much more attention than thus far. As a result, at the moment there is no possibility for independent agricultural production. , KMBT_363
- Full Text:
- Date Issued: 2004
The wing coupling apparatus and the morphometric analysis of honeybee populations
- Hepburn, H Randall, Radloff, Sarah E
- Authors: Hepburn, H Randall , Radloff, Sarah E
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:6904 , http://hdl.handle.net/10962/d1011760
- Description: Significant differences between countries were found in the distribution of the number of hamuli within Apis andreniformis, A. florea, A. cerana and A. koschevnikovi. The mean hamuli numbers for Apis mellifera intermissa differed significantly among localities in Algeria. Significant differences in intercolonial variability between countries were found within A. cerana. There was no significant infraspecific variability within A. andreniformis, A. florea, A. koschevnikovi and A. m. intermissa. Significant differences in the mean number of hamuli occur between A. m. intermissa and A. andreniformis, A. florea and A. cerana; also between A. cerana/A. koschevnikovi and A. andreniformis and A. florea. Significant differences were found in the distribution and variability of the number of hamuli between species (populations). The mean numbers of hamuli for A. andreniformis differed from those of A. florea. Both these population means differed from those of A. cerana, A. koschevnikovi and A. m. intermissa. No significant differences were found between A. cerana and A. koschevnikovi. When the analysis included data for A. dorsata, A. nigrocincta, A. m. carnica, A. m. caucasica and A. m. ligustica, the results showed significant differences in hamuli numbers between A. andreniformis/A. florea and A. cerana/A. koschevnikovi/A. nigrocincta and A. m. intermissa/A. m. carnica/A. m. caucasica/A. m. ligustica. Hamuli numbers in A. dorsata significantly differed from those of other populations except A. m. intermissa. These results show that hamuli numbers are useful in the classification of honeybee populations. Whether hamuli would be useful in multivariate analysis depends on the correlation between the number of hamuli and the other characters used.
- Full Text:
- Date Issued: 2004
- Authors: Hepburn, H Randall , Radloff, Sarah E
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:6904 , http://hdl.handle.net/10962/d1011760
- Description: Significant differences between countries were found in the distribution of the number of hamuli within Apis andreniformis, A. florea, A. cerana and A. koschevnikovi. The mean hamuli numbers for Apis mellifera intermissa differed significantly among localities in Algeria. Significant differences in intercolonial variability between countries were found within A. cerana. There was no significant infraspecific variability within A. andreniformis, A. florea, A. koschevnikovi and A. m. intermissa. Significant differences in the mean number of hamuli occur between A. m. intermissa and A. andreniformis, A. florea and A. cerana; also between A. cerana/A. koschevnikovi and A. andreniformis and A. florea. Significant differences were found in the distribution and variability of the number of hamuli between species (populations). The mean numbers of hamuli for A. andreniformis differed from those of A. florea. Both these population means differed from those of A. cerana, A. koschevnikovi and A. m. intermissa. No significant differences were found between A. cerana and A. koschevnikovi. When the analysis included data for A. dorsata, A. nigrocincta, A. m. carnica, A. m. caucasica and A. m. ligustica, the results showed significant differences in hamuli numbers between A. andreniformis/A. florea and A. cerana/A. koschevnikovi/A. nigrocincta and A. m. intermissa/A. m. carnica/A. m. caucasica/A. m. ligustica. Hamuli numbers in A. dorsata significantly differed from those of other populations except A. m. intermissa. These results show that hamuli numbers are useful in the classification of honeybee populations. Whether hamuli would be useful in multivariate analysis depends on the correlation between the number of hamuli and the other characters used.
- Full Text:
- Date Issued: 2004
Thermal and photostability studies of triprolidine hydrochloride and its mixtures with cyclodextrin and glucose
- Authors: Ndlebe, Vuyelwa Jacqueline
- Date: 2004
- Subjects: Antihistamines , Glucose , Cyclodextrins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4387 , http://hdl.handle.net/10962/d1005052 , Antihistamines , Glucose , Cyclodextrins
- Description: Triprolidine hydrochloride (C₁₉H₂₂N₂.HCl.H₂O) (TPH) is a well-known antihistamine drug. It melts between 118°C and 122°C and the amount of water present is 4.5 mass percent. TPH is reported as being photosensitive and must be stored in sealed, light-tight containers. The thermal stabilities of TPH and of 1:1 molar and 1:1 mass ratio physical mixtures of TPH with beta-cyclodextrin (BCD) and with glucose have been examined using DSC, TG and TG-FTIR, complemented by X-ray powder diffraction (XRD) and infrared spectroscopic (IR) studies. Thermal studies of the solid TPH/BCD mixtures indicated that interaction between the components occurs and it is possible that the TPH molecule may be least partially accommodated in the cavity of the BCD host molecule. XRD results support this indication of inclusion. The results for mixtures of TPH/glucose also suggest that there is interaction between the two components. The results of molecular modelling suggest that TPH is most likely to be accommodated in the BCD cavity as a neutral triprolidine molecule with the toluene portion of the molecule entering first. There is also an indication that the Z-isomer should be accommodated slightly more readily than the E-isomer. Photostability studies were done by irradiating thin layers of solid samples of TPH and its mixtures for various times at 40°C using an Atlas Sun test CPS lamp operating at 550 W h m⁻². An analytical method using HPLC was developed and validated to determine the amounts of any photodegradants. DSC, TG, FTIR, XRD and IR were also used examine the irradiated samples. XRD results showed that changes in the TPH crystal structure occurred during irradiation and that these changes increased with the time of irradiation. Irradiation for 20 hours with UV or exposure to sunlight showed the presence of degradants. The results obtained illustrate the general stability of TPH, especially in the solid state. Although the potential for isomerization to the pharmaceutically inactive Z-isomer exists, this transformation would require extreme light conditions. The study has also shown TPH to be compatible with both glucose and BCD, which are potential excipients both in solid and liquid dosage forms. The presents of these excipients in dosage forms will thus not adversely affect the stability and the therapeutic efficacy of TPH. . An analytical method using HPLC was developed and validated to determine the amounts of any photodegradants. DSC, TG, FTIR, XRD and IR were also used examine the irradiated samples. XRD results showed that changes in the TPH crystal structure occurred during irradiation and that these changes increased with the time of irradiation. Irradiation for 20 hours with UV or exposure to sunlight showed the presence of degradants.
- Full Text:
- Date Issued: 2004
- Authors: Ndlebe, Vuyelwa Jacqueline
- Date: 2004
- Subjects: Antihistamines , Glucose , Cyclodextrins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4387 , http://hdl.handle.net/10962/d1005052 , Antihistamines , Glucose , Cyclodextrins
- Description: Triprolidine hydrochloride (C₁₉H₂₂N₂.HCl.H₂O) (TPH) is a well-known antihistamine drug. It melts between 118°C and 122°C and the amount of water present is 4.5 mass percent. TPH is reported as being photosensitive and must be stored in sealed, light-tight containers. The thermal stabilities of TPH and of 1:1 molar and 1:1 mass ratio physical mixtures of TPH with beta-cyclodextrin (BCD) and with glucose have been examined using DSC, TG and TG-FTIR, complemented by X-ray powder diffraction (XRD) and infrared spectroscopic (IR) studies. Thermal studies of the solid TPH/BCD mixtures indicated that interaction between the components occurs and it is possible that the TPH molecule may be least partially accommodated in the cavity of the BCD host molecule. XRD results support this indication of inclusion. The results for mixtures of TPH/glucose also suggest that there is interaction between the two components. The results of molecular modelling suggest that TPH is most likely to be accommodated in the BCD cavity as a neutral triprolidine molecule with the toluene portion of the molecule entering first. There is also an indication that the Z-isomer should be accommodated slightly more readily than the E-isomer. Photostability studies were done by irradiating thin layers of solid samples of TPH and its mixtures for various times at 40°C using an Atlas Sun test CPS lamp operating at 550 W h m⁻². An analytical method using HPLC was developed and validated to determine the amounts of any photodegradants. DSC, TG, FTIR, XRD and IR were also used examine the irradiated samples. XRD results showed that changes in the TPH crystal structure occurred during irradiation and that these changes increased with the time of irradiation. Irradiation for 20 hours with UV or exposure to sunlight showed the presence of degradants. The results obtained illustrate the general stability of TPH, especially in the solid state. Although the potential for isomerization to the pharmaceutically inactive Z-isomer exists, this transformation would require extreme light conditions. The study has also shown TPH to be compatible with both glucose and BCD, which are potential excipients both in solid and liquid dosage forms. The presents of these excipients in dosage forms will thus not adversely affect the stability and the therapeutic efficacy of TPH. . An analytical method using HPLC was developed and validated to determine the amounts of any photodegradants. DSC, TG, FTIR, XRD and IR were also used examine the irradiated samples. XRD results showed that changes in the TPH crystal structure occurred during irradiation and that these changes increased with the time of irradiation. Irradiation for 20 hours with UV or exposure to sunlight showed the presence of degradants.
- Full Text:
- Date Issued: 2004